I signal almost all right turns. The exceptions are if I'm sure there's no one around (e.g. zig-zagging through the maze of backstreets I live near) or if I really need to keep both hands on the handlebars -- for instance, if the road surface is rough. In both cases I'll be in primary position.
I signal many left turns, especially if it means someone can avoid waiting for me to go past, but as Cyclecraft says, most left-signals are courtesy while most right-signals are for safety.
I signal many left turns, especially if it means someone can avoid waiting for me to go past, but as Cyclecraft says, most left-signals are courtesy while most right-signals are for safety.